S-90273A428 1/4"-20 x 5" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in demanding environments
• High tensile strength of 60,000 psi ensures reliable fastening under substantial mechanical loads
• Rockwell B70 hardness provides excellent durability and resistance to wear during installation and use
• Class 2A thread fit offers optimal assembly clearance while maintaining secure connections
• Partially threaded design allows for precise clamping force control in various material thicknesses
• 82° countersink angle enables flush mounting for clean, professional finishes
• Phillips No. 3 drive ensures efficient installation with standard driving tools

Professional Applications & Engineering Value

This 1/4-20 UNC flat head screw delivers exceptional engineering value for industrial assembly applications where flush mounting and high-strength fastening are critical. The zinc-plated steel construction provides reliable corrosion protection in manufacturing environments, while the coarse thread design ensures rapid installation and superior holding power in various materials. The partially threaded configuration allows engineers to precisely control clamping force, making these flat head Phillips screws ideal for machinery assembly, structural frameworks, and equipment manufacturing where vibration resistance and long-term reliability are paramount requirements.

Specification Summary & Compliance

Manufactured to exacting ASME B18.6.3 standards with Class 2A thread fit tolerances for consistent performance. Features UNC coarse threads with right-hand orientation and 5" length with minimum 1½" thread engagement. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across industrial applications while meeting international quality and safety standards.